there's a slight error in sendlink in the macro.. using old macro language
open your macros folder and look for firefox.kmm
open firefox.kmm in notepad or any text editor
you should find this part:
exec(sub("%1",$LINKURL,$_Firefox_CommandLine));
replace $LINKURL to $LinkURL
so the string becomes:
exec(sub("%1",$LinkURL,$_Firefox_CommandLine));
alternatively, you can download this fixed macro(rightclick-save target as)
http://necb.bizhat.com/kmeleon/firefox.kmm
save in your kmeleon\macros folder to replace the older firefox.kmm